Biosensor technology is now the method of choice to monitor in real-time the kinetics of biomolecular interactions. The technology offers high sensitivity, specificity and reproducibility, requires minute amounts of material, and is appropriate to the study of interactions between a wide range of biomolecules, including small organic molecules, proteins, nucleic acids, carbohydrates, and lipids. A broad literature demonstrates applications in studies of drug/receptor interactions, signal transduction, transcription, membrane proteins and immune regulation. Having the ability to measure these types of interactions are essential to five major research programs underway at SJCRH, yet we do not have this capability either in the institution or in the city. This application seeks funding for the purchase of a biosensor instrument, the Biacore 3000, to support these NIH-funded research efforts. The instrument will be incorporated into the Center for Biotechnology at St. Jude Children's Research Hospital.